Twin Studies and Eating Disorder Research

Contributor: Crystal Karges, MS, RDN, IBCLC, Special Projects Coordinator at Eating Disorder Hope/Addiction Hope

twins-632427_640The understanding we have of eating disorders today is far more in depth, informative and involved than what the general public had even a few years ago.

With ongoing research that has been completed in these population groups, eating disorders have been understood in a light of greater clarity that helps break many of the stigmas and myths that often surround these disorders. Examining the types of studies that have been done can give a better picture to the evidence that has been discovered from research efforts.

Studying Twins

One such population group that is helpful in understanding the complexity of eating disorders are twin pairs. Twin studies are an important tool in the field of behavioral genetics. This unique pairing allows researchers to study varying family environments and differing genetic makeup.

Identical twins share nearly 100% of their genes while fraternal twins share about 50 percent of their genes. Through the comparison of several hundreds of families of twins, scientists can better understand the roles of a shared environment, the impact of genetics, and possible unique environments that influence behavioral traits.

Differentiating Environment from Genetics

baby-772439_640Many important studies in the eating disorder community have been completed with twin methodology. Twin studies can be helpful in differentiating environmental effects from genetic ones by comparing similarity for a train/disorder between identical and fraternal twins1.

Research findings from twin studies on eating disorders have found significant genetic components for anorexia nervosa and bulimia nervosa, including behaviors and attitudes that are associated with clinical eating pathology1. Twin studies focused one eating disorders have also observed that variance in liability may be due to unique environmental factors, such as occurrences that are unique to siblings within the same family1.

Studying Behavioral Characteristics in Twins

Other twin studies have looked at behavioral characteristics among twin pairs, both identical and fraternal. One such study investigated the “thin-ideal internalization” in attempt to determine if genetic factors make women more susceptible to this outside pressure than others.

In order to explore the idealization of thinness, sets of twins were studied and evaluated. The results from this study showed that identical twin pairs had a closer level of thin idealization than that of fraternal twin pairs2.

The interesting findings from this twin study allowed researchers to surmise that genetics indeed plays a significant role in this area. Lead author of this study shared, “The broad cultural risk factors that we thought were most influential in the development of thin-ideal internalization are not as important as genetic risk and environmental risk factors that are specific and unique to each twin”2.

Insight into Treating and Understanding Eating Disorders

twins-435070_640While the research approach utilizing twin methodology may not be the perfect scenario, this form of study may help give important insight about these deadly psychiatric illnesses. With a better understanding about the factors that contribute to the progression of these disorders, including both genetic and environmental factors, treatment methods can be refined and improved for the eating disorder sufferer.

As with any research study, data should be analyzed carefully and results approached appropriately. Scientists have noted that although twin studies are powerful tools, the methodology can be obscure, as well as the implications misinterpreted if reviewed carefully.

Applying Evidence-based Treatments

As with all recommendations for eating disorder sufferers, make sure that best practices are being followed and evidenced-based treatment methods applied. Any conclusions determined by researchers should be carefully reviewed and shared in the appropriate context to help minimize misinterpretation of data and information.

The value of twin studies can be insurmountable in the eating disorder community but should also be interpreted with caution in order to provide the most helpful recommendations that are truly evidenced based.

Community Discussion – Share your thoughts here!

What are your thoughts on the importance of twin studies and eating disorder research? Have you ever participated in research as a twin? How do these types of studies propel the understanding of these mental health disorders?


References:

  1. Berrettini, Wade. “The Genetics of Eating Disorders.” Psychiatry (Edgmont) 1.3 (2004): 18–25. Print.
  2. “Twin-study shows eating disorders influenced by genetics”, Scienceagogo.com http://www.scienceagogo.com/news/20120903201223data_trunc_sys.shtml

Last Updated & Reviewed By: Jacquelyn Ekern, MS, LPC on July 31st, 2015
Published on EatingDisorderHope.com